Research

Effect of Pipe Material and Concentration of Sodium Hydroxide on the Rate of Corrosion

The purpose of the experiment was to determine the effects of pipe material and concentration of sodium hydroxide (NaOH) on the rate of corrosion of piping and if these factors are significant. This information will help to reduce the rate of corrosion in household pipes by informing homeowners of which type of pipe material they should purchase for their plumbing. Three different pipe materials were used: copper (low), PVC (standard), and PEX (high). The three sodium hydroxide concentrations used were 2%, 5%, and 10% concentration. Multiple trials were run with various combinations of pipe material and concentrations of sodium hydroxide to satisfy the requirements of a Two-Factor Design of Experiment (DOE). To determine the rate of corrosion, the researchers compared the change in mass over time. The results of the experiment concluded that the low-value pipe (copper) and the low-value sodium hydroxide concentration (2%) produced the largest rate of corrosion. The DOE concluded that the experiment resulted in no significant factors. This means that neither pipe material, concentration of sodium hydroxide, nor an interaction between the two had a significant effect on corrosion rate. This could have resulted from error in the experiment, particularly the time restraint. The researchers only tested for 22 straight days and did not see the results that they hypothesized.